检索结果-内蒙古大学图书馆

Sensorless Control of IPMSM Based on Regression Model

IEEE TRANSACTIONS ON POWER ELECTRONICS 2019年第9期34卷 9191-9201页

作者： Choi, Jongwon Nam, Kwanghee Bobtsov, Alexey A. Ortega, Romeo Pohang Univ Sci & Technol Dept Elect Engn Pohang 790784 South Korea ITMO Univ Dept Control Syst & Informat St Petersburg 197101 Russia CNRS SUPELEC Lab Signaux & Syst F-91192 Gif Sur Yvette France

A position-sensorless algorithm is developed for an interior permanent-magnet synchronous motor, while reflecting the saliency in an extended electromotive force term. Active flux is converted into a new linear regression form, and a high-pass filter was applied. Then, the gradient algorithm is applied to derive an estimate of the active flux in the stationary frame. The proposed observer is an inherently sensorless type because it does not require the rotor speed or position information. It is practically attractive since it does not require the use of pure integrator that is marginally stable. In addition, the observer can be constructed without the phase modulation flux linkage constant. It is basically a model-based method. However, it is easily extended to a signal injection method that is robust in the low-speed region. Ultimate boundedness is established using the persistency of excitation condition. Validity of the algorithm is demonstrated experimentally via torque and speed control with a full load in the low-speed range.

关键词： gradient algorithm interior permanent-magnet synchronous motor (IPMSM) linear regression form nonlinear observer persistency of excitation saliency sensorless control signal injection

来源：评论

学校读者我要写书评

暂无评论

PERFORMANCE ANALYSIS OF THE SMOOTHED LEAST MEAN-SQUARE (SLMS) algorithm

引用

SIGNAL PROCESSING 1986年第3期11卷 265-276页

作者： FEUER, A BERMAN, N Department of Electrical Engineering Technion-Israel Institute of Technology Technion City Haifa 32 000 Israel Department of Aeronautics Engineering Technion-Israel Institute of Technology Haifa 32 000 Israel

Stochastic gradient algorithms were thoroughly investigated. Results reported in the literature as well as experiments we have carried out indicate that their performance can be improved by the addition of a gradient smoothing element. This motivated us to present and study a version of the algorithm, with constant adaptation coefficients, which we named Smoothed Least Mean Square (SLMS). The well-known LMS algorithm turns out to be a special case of the SLMS. We develop equations governing the behavior of first- and second-order statistics of this algorithm and conditions for its convergence. Our study indicates that improved steady-state performance can be achieved by the additional smoothing process. Zusammenfassung Stochastische gradientenalgorithmen sind schon gründlich untersucht worden. Publizierte Resultate und eigene Experimente deuteten darauf hin, dass ihre Effizienz gesteigert werden kann, wenn der gradient zusätzlich geglättet wird. Dies motivierte uns, eine Version des algorithmus mit konstanten Adaptationskoeffizienten zu untersuchen. Der bekannte algorithmus des kleinsten mittleren Quadrates ist ein Spezialfall davon. Die Gleichungen für die Statistik erster und zweiter Ordnung werden für diesen algorithmus abgeleitet. Unsere Resultate weisen darauf hin, dass das Verhalten des algorithmus im stationären Zustand durch den Glättungsprozess verbessert werden kann.

关键词： Adaptive filters least mean square (LMS) gradient algorithm

来源：评论

学校读者我要写书评

暂无评论

Unsteady flow optimization by a stabilized finite element method

引用

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2010年第12期26卷 1915-1933页

作者： Gao, Zhiming Ma, Yichen Inst Appl Phys & Computat Math Lab Computat Phys Beijing 100088 Peoples R China Xi An Jiao Tong Univ Sch Sci Shaanxi 710049 Peoples R China

This paper presents the problem of shape optimization of two-dimensional viscous flow governed by the time-dependent Navier-Stokes equations. The minimization problem of the viscous dissipated energy was established in the fluid domain. The discretization of Navier-Stokes equations is accomplished using a new stabilized finite element method in space and finite difference in time. This new method does not need a stabilization parameter or calculation of high-order derivatives. We derive the structures of the discrete Eulerian derivative of the cost functional by a discrete adjoint method with a function space parametrization technique. A gradient-type optimization algorithm with a mesh adaptation technique and a mesh moving strategy is effectively implemented. Copyright (C) 2009 John Wiley & Sons, Ltd.

关键词： discrete adjoint method shape optimization stabilized finite element method gradient algorithm time-dependent Navier-Stokes equations

来源：评论

学校读者我要写书评

暂无评论

Equalisation of time-variant communications channels via channel estimation based approaches

引用

SIGNAL PROCESSING 1997年第2期60卷 181-193页

作者： Shimamura, T Semnani, S Cowan, CFN Department of Information and Computer Sciences Saitama University 255 Shimo-Okubo Urawa 338 Japan Center for Human Communications British Telecomunication Laboratory Martlesham Ipswich IP5 7RE UK Department of Electrical and Electronic Engineering The Queen's University of Belfast Ashby Building Stranmillis Road Belfast BT9 5AH UK

For the purpose of tackling the problem of equalisation in a time-variant environment, two novel approaches are developed in which the separation of the channel estimation process from the equalisation process is attempted. Two linear filters - channel estimator and equalisation filter - are used to reconstruct the transmitted sequence. The gradient algorithm with degree-1 least square fading memory prediction is adopted for the channel estimator. Using the results produced by the channel estimator, the coefficients of the equalisation filter are indirectly updated. Computer simulation results show that the two channel estimation based adaptive equalisers provide significant improvement in the case of a second order Markov communication channel model. (C) 1997 Elsevier Science B.V.

关键词： time-variant channel adaptive equaliser channel estimator gradient algorithm Kalman filter

来源：评论

学校读者我要写书评

暂无评论

Optimization of ACE mode transition control schedule considering geometric adjustment speed

引用

INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES 2024年第Sup1期40卷 s389-s398页

作者： Song, Keran Jia, Linyuan Chen, Yuchun Tan, Tian Fan, Peiyang Northwestern Polytech Univ Sch Power & Energy Xian 710072 Peoples R China

Aiming to optimize the mode transition control schedule of the adaptive cycle engine (ACE), an optimization method based on a gradient algorithm was proposed. During the mode transition, the compressor surge margin, the total turbine inlet temperature and the combustion chamber fuel-air ratio are not exceeded. The integration of thrust by time was selected as the optimization objective. The geometric parameters were updated via the optimization target derivative. The speed limit of the geometric adjustment mechanism was also considered in the optimization process. The control schedules of two mode transition processes, from triple to double bypass mode and from double to triple-bypass mode were optimized. The optimization method presented in this paper can be applied to various mode transitions and the geometric adjustment speed meets all the constraints.

关键词： ACE geometric adjustment schedule gradient algorithm mode transition

来源：评论

学校读者我要写书评

暂无评论

Global stability of adaptive IIR filters based on the output error method and parameter truncation

引用

CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2004年第3期23卷 231-254页

作者： Radenkovic, M Bose, T Univ Colorado Dept Elect Engn Denver CO 80127 USA Utah State Univ CHIP Logan UT 84322 USA

This paper presents a rigorous proof of global stability of an adaptive infinite impulse response filter based on the output error method. The underlying idea of the developed analysis is the construction of suitable Lyapunov functions for different phases of adaptation. The considered estimator is an algorithm with a nonvanishing gain sequence. In order to prevent drift along an unstable manifold, a truncation of parameter estimates is incorporated. Such an algorithm is suitable for nonstationary signals.

关键词： parameter estimation gradient algorithm IIR filter convergence global stability adaptive filter

来源：评论

学校读者我要写书评

暂无评论

Discrete optimal couple tracking: A control scheme for electrical-tuning of strong coupling piezoelectric energy harvesters

引用

JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES 2023年第7期34卷 785-799页

作者： Morel, Adrien Pillonnet, Gael Gibus, David Badel, Adrien Univ Savoy Mt Blanc SYMME 7 Chemin Bellevue F-74000 Annecy France Univ Grenoble Alpes CEA Leti Grenoble France

In order to track the maximum power point of piezoelectric energy harvesters, an effective approach consists in designing interfaces able to electrically tune the harvester dynamics. Such interface should exhibit-at least-two tunable parameters in order to independently optimize the harvester damping and resonant frequency, that is, an electromechanical impedance matching of the real and imaginary parts of the electrical load. In order to optimize and control these two parameters, it is necessary to implement two control loops that simultaneously impact the harvester dynamics. Furthermore, these loops should combine quick convergence time with low-power consumption in order to react sufficiently fast to compensate for any shift in the vibration frequency and to consume only a small portion of the harvested power. In this paper, we propose a control-law based on the successive evaluation of couples of parameters in order to select the optimal one. First, we determine analytically the expression of a set of optimal couples valid for any two-parameters electrical interfaces. Thereafter, we prove that only a few well-chosen couples of parameters are sufficient to maximize the power on a large frequency band. The proposed methodology has been experimentally verified on a tunable interface, the short-circuit synchronous electric charge extraction. Combined with a strongly coupled piezoelectric energy harvester, we have been able to maintain the harvested power close to the maximal achievable power (i.e. >70% of the maximal achievable power) on a 20 Hz frequency band, with only five couples of parameters. Such approach allows to substitute a multi-parameters convergence algorithm by a single-couple of parameters convergence algorithm, greatly simplifying the algorithm and reducing its convergence time.

关键词： Piezoelectricity vibration energy harvesting nonlinear electronics discrete maximum power point tracking predictive model gradient algorithm frequency tuning broadband

来源：评论

学校读者我要写书评

暂无评论

Simultaneous Optimization of Mismatched Filters and Controlled Amplitude Signals for Long-Range MIMO Radars

引用

IEEE ACCESS 2022年 10卷 108251-108260页

作者： Bezousek, Pavel Karamazov, Simeon Univ Pardubice Fac Elect Engn & Informat Pardubice 53210 Czech Republic

This study presents a new signal and filter design procedure for long-range multiple-input multiple-output (MIMO) radars with a pulse length shorter than the return time of signals reflected by the most distant targets. The proposed algorithm adopts and radically improves the method of alternating the optimization of filters and signals, which was recently published by the same authors. It introduces full control of the signal envelope variation during the pulse, preserving acceptable peak-to-average power ratio (PAR) and signal-to-noise ratio (SNR) loss values. This state-of-the-art method allows calculation simplicity and is important for high-speed computations in adaptive applications. A gradient algorithm was used for the signal amplitude and phase optimization. The signal amplitude was controlled using a special signal construction consisting of two complex exponentials.

关键词： Optimization Filtering algorithms Crosstalk Radar Matched filters MIMO radar Signal to noise ratio Iterative methods Quadratic programming Noise measurement Crosstalk Doppler effect iterative optimization gradient algorithm MIMO radar peak to average power ratio quadratic programming separation filter side lobe signal envelope signal to noise ratio

来源：评论

学校读者我要写书评

暂无评论

Optimal shape design for Stokes flow via minimax differentiability

引用

MATHEMATICAL AND COMPUTER MODELLING 2008年第3-4期48卷 429-446页

作者： Gao, Zhiming Ma, Yichen Zhuang, Hongwei Xian Jiaotong Univ Sch Sci Shaanxi 710049 Peoples R China Engn Coll Armed Police Force Shaanxi 710086 Peoples R China

This paper is concerned with the shape sensitivity analysis of a viscous incompressible fluid driven by Stokes equations with a nonhomogeneous boundary condition. The structure of the shape gradient with respect to the shape of the variable domain for a given cost function is established by using the differentiability of a minimax formulation involving a Lagrangian functional combined with the function space parametrization technique and the function space embedding technique. We apply a gradient type algorithm to our problem. Numerical examples show that our theory is useful for practical purposes and the proposed algorithm is feasible. (c) 2008 Published by Elsevier Ltd

关键词： shape optimization minimax formulation gradient algorithm Stokes equations

来源：评论

学校读者我要写书评

暂无评论

Determination of high power synchronous generator subtransient reactances based on the waveforms for a steady state two-phase short-circuit

引用

APPLIED MATHEMATICS AND COMPUTATION 2018年 319卷 538-550页

作者： Berhausen, Sebastian Bobon, Andrzej Silesian Tech Univ Inst Elect Engn & Comp Sci Akad 10 PL-44100 Gliwice Poland

In the paper, there is presented an analysis of the waveforms at the stator winding terminals of a high power synchronous generator for a steady state two-phase short-circuit. The analysis was performed by the finite element method based on a 2D generator model taking into account higher spatial and time harmonics of the magnetic field as well as the impact of eddy currents in the rotor damping circuits. The used FE model was experimentally verified. For the steady state two-phase short-circuit, the waveforms determined by the FE method were compared with the approximated waveforms calculated using analytical formulas. The analytical formulas were derived from the machine equations written in the stator fixed coordinate system (alpha, beta, 0), using normalized transformation of coordinates and the Heaviside operational calculus. The higher time harmonics obtained based on the FFT analysis of the waveforms of the short-circuit current and open phase voltage were used for determining subtransient reactances in the d and q axes of a 200 MW generator. The thus determined generator reactances were compared with the values determined by other methods. (C) 2017 Elsevier Inc. All rights reserved.

关键词： Synchronous generator Line-to-line short circuit 2D field-circuit model Fast Fourier transform (FFT) Least-squares method gradient algorithm

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：